신규 하프-메탈로센 촉매의 개발과 이를 이용한 올레핀 중합
Synthesis of Novel Half-Metallocene Complexes and Their Olefin Polymerization
- 주제(키워드) Bimetallic , Constrained Geometry Catalyst , Titanium complexes , Polymerization
- 발행기관 아주대학교 대학원
- 지도교수 이분열
- 발행년도 2008
- 학위수여년월 2008. 2
- 학위명 석사
- 학과 및 전공 일반대학원 분자과학기술학과
- 본문언어 영어
초록/요약
1. Suzuki-coupling reaction of 2,6-dibromo-4-R-anilnes (R = Me, F) with 2 equivalents of 2-dihydroxyboryl-3-methyl-2-cyclopenten-1-one (1) affords cyclopentenone compounds, 2,6-[3-MeC5H4(=O)]2-4-R-C6H2NH2, from which aniline compounds containing two dimethylcyclopentadiene units on 2 and 6 positions, 2,6-[2,5-Me2C5H3]2-4-R-C6H2NH2, are afforded by the addition of MeLi and subsequent work-up with aqueous HCl. Successive treatment of Ti(NMe2)4 and Me2SiCl2 to the ligands yields bimetallic dichlorotitanium complexes {2,6-[？？5-2,5-Me2C5H2]2-4-R-C6H2N-？？N}{TiCl2}2 (7, R = Me; 8, R = F) where a nitrogen atom coordinates to both titanium centers. Solid structure of 7 was determined by X-ray crystallography. Bimetallic titanium complexes, 4,4'-A[{2-(？？5-2,3,5-Me3C5H)C6H3NC6H11-？？N}TiCl2]2 (18, A = CH2; 19, A = O; 20, A = ortho-C6H4) are prepared by the similar synthetic strategy applied for 7 and 8. Dinuclear complexes 7 and 8 are not active for the ethylene/1-hexene copolymerization. Complexes 18-20 are highly active and the activities are higher than that observed for the mononuclear analogue, {2-(？？5-2,3,5-Me3C5H)C6H3NC6H11-？？N}TiCl2. Molecular weights of the polymers obtained with bimetallic complexes are higher than that of the polymer obtained with the mononulcear complex. The slightly higher content of the long-chain-branching is observed for the copolymers obtained with the bimetallic system. Keywords: Bimetallic, Constrained Geometry Catalyst, Titanium complexes, Polymerization 2. o-Phenylene-bridged trimethylcyclopentadienyl/amido titanium complexes [(？？5-2,3,5-Me3C5H)-C6H4NR-？？N]TiCl2 (18, R = CH3; 19, R = CH2CH3; 20, R = CH2C(CH3)3; 21, R = CH2(C6H11)) and zirconium complexes [(？？5-2,3,5-Me3C5H)-C6H4NR-？？N]ZrCl-？？Cl2-ClZr[(？？5-2,3,5-Me3C5H)-C6H4NR-？？N] (22, R = CH3; 23, R = CH2CH3; 24, R = CH2C(CH3)3; 25, R = CH2(C6H11); 26, R = C6H3; 27, R = CH(CH2CH3)2) are prepared via a key step of the Suzuki-coupling reaction between 2-dihydroxyboryl-3-methyl-2-cyclopenten-1-one (2) with the corresponding bromoaniline compounds. Molecular structures of the titanium complexes 14 and 15 and the dimeric zirconium complexes 25 and 26 are confirmed by X-ray crystallography. The Cp(centroid)-Ti-N and Cp(centroid)-Zr-N angles are, respectively, smaller than those observed for Me2Si-bridged complexes [Me2Si(？？5-Me4C5)(NtBu)]TiCl2 and its Zr-analogue indicating the o-phenylene-bridge provides more constrained nature in the complexes than the well-known Me2Si-bridge. Complexes 7b-7e show comparable activities to the CGC when they are activated with [Ph3C]+[B(C6F5)4]- in the presence of excess of Al(iBu)3. Complexes 8-10 show higher activity than the CGC. All the complexes except 7f incorporate higher amount of 1-hexene than the CGC. Molecular weights of all the polymers except the one obtained by 10 are higher than that of the polymer obtained by the CGC.
more목차
Chapter 1 Bimetallic Phenylene-Bridged Cp/amide Titanium Complexes and Their Olefin Polymerizations = 1
1. Introduction = 2
2. Result and Discussion = 3
2.1 Synthesis and Characterization = 3
2.2 X-ray Crystallographic Studies = 6
2.3 Polymerization Studies = 8
3. Summary = 12
4. Experimental Section = 12
5. References = 30
6. Supplement = 32
Chapter 2 o-Phenylene-Bridged Cp/amido Titanium and Zirconium Complexes and Their Polymerization Reactivity = 36
1. Introduction = 37
2. Result and Discussion = 39
2.1 Synthesis and Characterization = 39
2.2 X-ray Crystallographic Studies = 42
2.3 Polymerization Studies = 45
3. Experimentals = 48
4. References = 66
5. Supplement = 69
